Circuit interrupter



Dec. 1, 1942. H. L. RAWLINS ET-AL 2,303,496

' CIRCUIT INTERRUPTER Filed Sept. 19, 1940 2 Sheets-Sheet 1 jaw/014a 0H. L. RAWLINS ETAL CIRCUIT INTERRUPTER Filed Sept. 19, 1940 2Sheets-Sheet 2 INVENTORS WITNESSES:

fifiefiiiii BY z/ A'ITORNEY Patented Dec. 1, 1942 OFFICE CIRCUITINTERRUPTER Herbert L. Rawlins, Wilkinsburg, and Carl A. Ringbloom,Turtle Creek, Pa., assig'nors to Westinghouse Electric & ManufacturingCompany, East Pittsburgh, Pa., a corporation of Pennsylvania ApplicationSeptember 19,1940, Serial No. 357,392

14 Claims.

This invention relates generally to circuit interrupters, and morespecifically to improvements in disconnecting switches.

Modern disconnecting switches, especially of the outdoor type, usuallyemploy relatively high contact pressures at the separable contactsthereof. Because of exposure to the atmosphere, it is also preferablethat the contacts have a wiping action to insure the maintenance ofclean contact surfaces. Certain diificulties have been encountered inapplying these features to disconnecting switches because they must besupported on relativel long insulators which have little resistance tolateral bending forces, and consequently, heretofore, relatively complexoperating mechanisms have been resorted to, to obtain the requiredmechanical advantage, and in some instances three or moresupportinginsulators have been used to obtain the desired lateralsupport.

One object of this invention is to provide a novel simplified form ofdisconnecting switch having high pressure separable contacts.

Another object of this invention is to provide novel actuating means formoving a disconnecting switch blade substantially longitudinally intoand out of pressure engagement with a contact, and substantiallylaterally toward and away from the contact to provide a relatively largeair gap in the circuit.

Another object of this invention is to provide a disconnecting switch ofthe type described, wherein the break contact is of a novel enclosedconstruction.

Another object of the invention is to provide novel separabledisconnecting contacts which may be engaged upon relative movement inany of a plurality of difierent directions.

Another object of this invention is to provide in a disconnecting switchof the type described, novel means for movably supporting thedisconnecting switch blade.

A further object of the invention is to provide novel arcing hornstructure for a disconnecting switch of the type described.

A still further object of this invention is to provide a disconnectingswitch of the type described, wherein the lateral stresses on theinsulator supports are maintained low enough to permit mounting of theentire switch and operating means therefor on two supporting insulators.

These and other objects of this invention will become more apparent uponconsideration of thefollowing detailed specification of a preferredembodiment thereof when taken in connection with the attached drawings,in which:

Figure 1 is a plan view of a disconnecting switch embodying myinvention;

Fig. 2 is a side elevational view of the switch shown in Fig. 1 with thecontact supporting housings shown in section;

Fig. 3 is a plan view of the switch shown in Figs. 1 and 2 with thecontact supporting housings in section, and with the switch shown in anopen position, with certain parts thereof removed;

Fig. 4 is a view similar to Fig. 3, but showing the switch in a positionadjacent its closed position;

Fig. 5 is a front elevation View of the stationary contact supportinghousing structure taken on substantially the line V-V of Fig. 2;

Fig. 6 is an enlarged sectional view through the stationary contact jawstaken substantially on the line VI--VI of Fig. 2; and

Fig. '7 is a schematic view showing a form of operating mechanism forthe switch.

Referring to the drawings, there is shown a switch mounted on asupporting base 2. A stationary insulator 4 is secured to the base2,'for example, as by the bolts 6, and carries at the outer end thereofa contact housing 8. The housing 8 comprises a cover plate I0 spacedfrom the end cap of the insulator 4 by downwardly projecting integralside wall portions l2, and the cover plate is secured in fixed relationto the insulator 4 by bolts l4 passing through the cover plate to bethreadedly engaged with the end cap of the insulator. The cover plateIllis provided with a forward integral downwardly extending flange I6and with a rear integral downwardly extending portion l8, to which issecured spaced contact jaws 29. As shown, the contact jaws 20 are in theform of elongated plate members, and are secured to the extension l8 ofthe cover plate by bolts 22 extending therethrough and through aterminal plate 24 disposed with one end between the contact jaw 26, tothereby space the jaws apart. The terminal plate 24 projects rearwardlybeyond the contact housing 8 for connection of a line conductor thereto.The forward ends of the contact jaws 20 are connected by a tension bolt26, having resilient cup-shaped washers 28 at the respective outer sidesof the contact jaws 29 to resiliently oppose separation of these jaws.

Forwardly of the tension bolt 25, the contact jaws '29 are provided withraised limited area contacting portions 39 on the opposed inner faces ofthe jaws. Referring to Fig. 6, it can be seen that these limited areacontact portions 30 are pressed out of the material of the contact jaws2e, and are provided on their confronting raised surfaces with grooves32, forming a plurality of line contacting portions adapted to engage acontact tongue when inserted therebetween. These line contactingportions extend substantially parallel to the longitudinal axis of thecontact jaws 26. It will also be noted that the forward ends of thecontact jaws 20 adjacent the limited area contact portions 30 have theside edges 34 thereof, and outer ends 36 bent outwardly with respect toeach other to form flared entrances to the space between the contactjaws. A closure member is provided for closing the forward end of thecontact housing 8, and this closure member is preferably provided with abase plate portion 38 adapted to be secured to-the end cap of theinsulator 4, as, for example, by bolts 40. The closure member alsoincludes an upwardly projecting integral flange 42 projecting upwardlyin the plane of, and towards flange IS on cover plate l0, butterminating at a point spaced therefrom to provide between these flangedportions an elongated slot aligned with the space between the contactjaws 20, to permit a switch blade to enter the contact housing and intothe space between the contact jaws. The flange 42, as seen in Fig. 5, isprovided with an integral, upwardly projecting stop lug 43, for definingthe end of the entrance slot. This lug may extend into engagement withthe cover plate l8, as shown. The housing closure member may also beprovided with a rear upwardly extending flange 44, if desired, forreinforcing purposes.

Also mounted on the supporting base 2 at a point spacedfrom thestationary insulator 4, is a rotatable insulator 46 having a supportingshaft 50 rotatably mounted in a bearing 48 in the base 2, The bearing48may be secured to the base 2 in any suitable manner, such as by bolts54. On the insulator supporting shaft 50, there is provided an actuatinglever 52 secured to integral flanged portions of the shaft-forexample,as by through bolts 56. A blade supporting enclosure 58 issecured to the end cap of insulator 46, for example, as by bolts 62,passing through the base plate 60 of said enclosure, to be threadedlyengaged with the insulator end cap. This enclosure further includes afront wall 64 extending upwardly from and integral with the jections l8integral with the front wall 64 of the enclosure, to thereby maintainthe springs in operative position. It will be noted in connection withthe spring supporting means that the front wall 64 of the enclosure 58is provided with two spaced sets of projections 18 to accommodate ablade supporting member mounted as shown in the drawings, or mounted formovement in the opposite direction, or in other words, with the bladesupporting member rotated at 180 about its longitudinal axis fromtheposition shown. A switch blade 80 has one end thereof secured on theouter end of the blade supporting element I0 by bolts 82, and thesebolts 82 may be utilized base plate 60, and this front wall is providedwith a transverse slot 68 through which a blade support 10 extends. Alsointegral with the front wall 64 and extending rearwardly therefrom andsubstantially parallel with respect to base plate 60, is a top plate 68substantially triangular in form, and for a purpose to be hereinafterdescribed.

Between the top plate 68 and base plate 60, there is mounted theenlarged head of a substantially T-shaped blade supporting element 10.It can be readily observed that the head portion of the blade support 10mounted within the blade supporting enclosure, is provided withoppositely extending lateral extensions at one end thereof to formspring supporting sockets 14 at opposite sides of supporting element 10.One end of the head of support 10, is provided with a bearing portionforpivotally receiving a pivot pin I2, offset or eccentric with respectto the axis of rotation of insulator 45, and with respect to thelongitudinal axis of the blade supporting member. Coil compressionsprings 16 are adapted to be positioned both above and below the slot inthe enclosure 58 with one end of each spring seated in a socket 14 inthe blade supporting head, and the other ends thereof fitting over protoclamp to the blade one end of a flexible shunt 84 of a flexibleconducting material such, for example, as copper braid or the like. Theother end of the flexible shunt 84 is secured to a terminal plate 88,one end of which is provided with an integral transversely extendingbearing 90 adapted to receive a pivot pin 92 supported between the baseplate 68 and top plate 68 of the blade supporting enclosure 58;Obviously, a line conductor 94 may be secured to the terminal plate 88by the same bolts 86 which secure the shunt 84 thereto, and by reason ofthe pivotal connection 92 the terminal plate may remain stationaryduring rotation of the rotatable insulator 46 and blade supportingenclosure 58.

In the operation of the parts of the switch thus far described, assumingthe switch to be in open position as shown in Fig. 3 of the drawings, itwill be observed that the coil compression springs 16 will maintain theswitch blade and its support 10 in a position where one edge thereof isin engagement with the end of slot 66 in the blade supporting enclosure.which is adjacent contact housing 8, Now if the rotatable insulator 46is rotated by operating crank 52 in a counterclockwise direction, asviewed in Fig. 3, the insulator and parts carried thereby will be movedto the position shown in Fig. .4, with the blade entering the spacebetween flanges l6 and 42 of the contact supporting enclosure 8, untilthe end of the blade comes into engagement with stop lug 43 on flange 42of the contact enclosure. This position of the parts is shown in Fig. 4of the drawings, and it will be noted that at this time the blade hasnot yet made engagement with the contact jaws 20. It will be apparentthat, upon continued counterclockwise rotation of insulator 46 from theposition shown in Fig. 4, the blade 80 will rotate on pivot 12 relativeto the insulator 45 and will thereby be moved substantiallylongitudinally into the space between the contact jaws 20. The blade ispreferably slightly larger in thickness than the distance between thelimited area contacting portions 30 of the contact jaws, so that thislongitudinal movement of the blade into engagement therewith isaccompanied by a slightseparation of the contact jaws opposed by theresilient washer members 28. It will also be noted that thislongitudinal movement of the switch blade is accomplished by means of arelatively great mechanical advantage. since a lever arm of the distancebetween pivot 12 and the axis of rotation of insulator 4B is used,instead of a lever arm equal to the length of the switch blade. It can,therefore, readily be seen that the lateral forces on the rotatableinsulator when moving the blade longitudinally into pressure engagementwith contact jaws 20 are substantially less than they would be if theblade were fixed withrespect to the rotatable insulator,

Another important result obtained by longitudinal movement of the switchblade into engagement with the limited area contacting portions '30 ofthe contact jaws is that, since the blade moves substantially parallelwith the line contacting portions of the limited area contacts 30, thesecontacting portions may cut their own grooves in the switch blades andthereby obtain even contact throughout the length of these portions,which contact, being limited in area, will obviously be under arelatively high pressure and thereby provide an exceptionally goodcontact between the outer end of the switch blade and the contact jaws20.

The fully closed position of the switch is shown in Figs. 1 and 2, andif it is desired to open the switch, it is obvious that it is merelynecessary to rotate the insulator 46 in a clockwise direction from theposition shown in Figs. 1 and 2, and that the first portion of thismovement will cause relative rotation of the switch blade supportingmember F about pivot pin 12 aided by coil compression springs 76, andthis will act to withdraw the outer end of the switch bladesubstantially longitudinally from between the contact jaws 20 until theparts reach the position shown in Fig. 4 of the drawings. At this point,the switch blade has been withdrawn from the plane of contact jaws 20and is able to engage with the adjacent end of slot 66 in the bladesupporting housing, whereby continued rotation in a clockwise directionfrom the position shown in Fig. 4 will cause positive pivotal movementof the switch blade with insulator 46, and thereby move the blade out ofthe contact supporting enclosure 8 to a position such as that shown inFig. 3, to insert a relatively large air gap in the circuit.

It is believed obvious from the foregoing that the switch blade has twodistinct successive movements in both its opening and closingoperations. In other words, in closing, the blade first moves pivotallyinto proximity to the stationary contact jaws 2H, and thereafter ismoved substantially longitudinally into pressure engagement betweenthese jaws. On opening the switch, the reverse sequence of movementstakes place; that is, the blade is first withdrawn substantiallylongitudina-lly from intimate engagement with contact jaws 2B, and isthereafter pivotally moved to a position away from the contact jaws toprovide a relatively wide air gap in the circuit.

Referring to Fig. 5, it will be noted that both the flange It on the topwall of contact enclosure 8 and flange 42 are provided with inclinedrelatively outwardly flaring edge portions 98 and 96, respectively, toguide the switch blade into the space between these flanges and align thsame in a position to enter between the contact jaws 20, It is also tobe noted that the slot provided between flanges IB and 42 of the contactenclosure 8 at the open end thereof extends along one side of thelimited area contact portions 38 of the contact jaws, so that in theevent the switch blade is not, for any reason, maintained by coilsprings I6 relative to the blade supporting enclosure in the positionshown in Figs. 3 and 4, the switch can still be closed, since the blademay enter between the contact jaws Zil from one side thereof due to thewide opening in the contact housing and aided by reason of the outwardlybent side edges 34 of the contact laws 28. This might oc-- cur uponfailure of coil springs I6, or if for some other reason the bladesupporting enclosure became filled with a solid mass of dirt or debris,preventing relative pivotal movement of the blade supporting enclosureand of the blade proper.

"It should also be noted that but a single flexible shunt 84 is providedfor bridging both pivots 92 and 12 between the switch blade and terminalplate 88. Switch blades which have been constructed heretofore capableof moving with a compound movement in their opening and closingoperations have necessitated, as stated before, relatively complexstructures embodying many pivotal connections which necessitate aplurality of shunts for bridging these connections. The particulararrangement of applicants blade mounting, especially of the two pivotsreferred to above, readily permits simplification of such an arrangementby the use of a single shunt 84.

Arcing horns I09 and IE2 are provided to be secured to the blade andcontact housing 8, repectively, and are of a novel type to permit thecompound movement of applicants switch blade in its opening and closingoperations. As shown especially in Figs. 1 and 2, the arc horn I61]includes a loop portion I04 adapted to be secured to the switch blade 80at an intermediate portion thereof by a clamping plate I96 and bolts I68. The arcing horn I00 from the loop portion I04 has an inclinedportion I'll] extending upwardly, and a contacting portion II2 extendingfrom the inclined portion substantially parallel with respect to theswitch blade 80 and its path of movement,

and an outer end portion II4 bent substantially reversely with respectto the contacting portion II2 thereof. The are horn IOZ is also providedwith a loop portion IIB positioned within a plu rality of positioninglugs H9 provided on the upper outer surface of the contact housing 8 andsecured thereto, as, for example, by a bolt H8. From the loop portionM6, the arc horn I82 extends substantially vertically as at I20, andthen horizontally to form a contacting portion which is in a planeparallel to the switch blade and the contacting portion H2 of the arcinghorn I 60, but at an angle to th direction of movement of the switchblade and arcing horn I00. The outer end of the arcing horn IE2 isextended substantially vertically as at I24.

It can readily be seen that when the switch is opened, or moved from theclosed position shown ment during longitudinal movement of the switchblad out of engagement with contact jaws 20, and during the first partof the subsequent pivotal movement of the blade, and that these portionsof the arc horns will become disengaged only after the switch blade 80is moved out of engagement with contact jaws 20, and even away from theplane of the contact supporting housing 8. The are horns I00 and H12 arepreferably made of some conducting material which is resilient such, forexample, as a copper alloy. Upon closing the switch, the inclined end ofarc horn I00 formed by the reverse loop IM will first engage with thecontacting portion I22 of arc horn I02, and by a camming action will beslightly stressed so that the contacting portions of the arc horns willbe maintained in engagement under some resilient stress.

It will be observed that when the switch is closed, the coil springs I6have some tendency to open the switch by virtue of the fact that whenthe switch is closed these springs are compressed, and hence when theswitch is in a fully closed position, the springs, as viewed in Fig. 1,bias the blade supporting enclosure 58 and blade support II! in oppositedirections for relative movement about the pivot pin 12.. Obviously,such movement mightcause. longitudinal withdrawal of the end of theswitch blade from between contact jaws 20. Although these springs I6 arepreferably not very strong, since it is only necessary that they bestrong enough to move the switch blade into engagement with one end ofslot 66 when the switch is opened, nevertheless, to prevent thepossibility of these springs from causing disengagement of the switch,an operating mechanism for the switch, such as shown in Fig. 7, may beemployed. The mechanism shown in Fig. 7 includes a link I26 pivotallyconnecting to the operating crank 52 of the rotatable insulator at oneend thereof, and having its other end pivotally connected to anintermediate portion of an operating lever I28. The operating lever I28is pivoted at one end I3I on a fixed support I30, and in the closedposition of the switch is in engagement with a fixed stop I32.Obviously, if the operating lever I28 be moved in the direction of thearrow shown in Fig. 7, the connecting link I26 will be moved over thecenter of pivot I3I and the switch opened. In closing, the reversemovement of the operating lever takes place, and when link I26 movesfrom below pivot I3I to above this pivot, as shown in Fig. '7, itobviously passes over center and any force inherent in the switch bladeto open itself is obviously prevented, because the operating handle I28is in engagement with stop I32 and cannot move in a direction towardsthe switch. Movement of the operating link I26 over the center of pivotI3I is permitted by a certain amount of play in the connections of thelinks and levers. While the particular mechanism illustrated in Fig. 7is relatively simple and particularly adapted for operatingdisconnecting switches of this type, it is obvious that other types ofmechanism embodying some sort of locking means, when the switch is inits fully closed position, could be used.

From the foregoing it should be apparent that the interrupter disclosedabove in the form of a disconnecting switch provides relatively simplemeans for obtaining compound movement of the switch blade with arelatively great mechanical advantage. This invention also comprehendsthe particular arrangement of limited area line contact portions whichare engaged or disengaged by a contact movable substantially in thedirection of the line contacts. There has also been disclosed novelforms of arcing horns especially adapted for switches of the typewherein the switch blade is provided with a compound motion in itsopening and closing operations. The entire switch structure, taken as awhole, is obviously of simplified form, while at the same time it is ofa sturdy construction. The fixed contact of the switch is entirelyenclosed in a housing in a novel manner, as are the movable supportingportions of the switch blade. This not only provides for an extremelyneat-appearing switch, but one which is also extremely practical in thataccess of the elements and debris to moving or contacting parts of theswitch is thereby precluded.

Having described preferred embodiments of the invention in accordancewith the patent statutes,

it is desired that the invention be not limited to the particularembodiments disclosed herein, inasmuch as it will be obviousparticularly to persons skilled in the art that many changes andmodifications may be made in this particular structure without departingfrom the broad spirit and scope of the invention. Therefore, it isdesired that the invention be interpreted as broadly as possible, andthat it be limited only by what is expressly stated in the followingclaims and by the prior art.

We claim as our invention:

1. In a circuit interrupter, hollow movable contact supporting andactuating means, an opening in said means, contact means extendingthrough said opening and movably mounted in said supporting means formovement relative thereto and limited by opposite ends of said opening,terminal means also extending into said supporting member and movablymounted therein, and a single flexible shunt means connecting saidterminal and contact means, for spanning said movable mountings.

2. Circuit interrupting means including a rotatable insulator carrying ahollow blade supporting means, blade means pivotally mounted in saidsupporting means on an axis eccentric with respect to the'axis ofrotation oi said insulator and extending through an opening in saidhollow supporting means, a second insulator carrying hollow contactsupporting means, contact means therein, an opening in said contactsupporting means for receiving the outer end of said blade means in itspivotal movement with said rotatable insulator, one end of said openingin said contact supporting means constituting a stop for said blademeans in its closing movement, whereby continued movement of saidrotatable insulator in the same direction causes relative substantiallylongitudinal movement of said blade means into intimate engagement withsaid contact means, arcing horns mounted on said blade means and contactsupporting means,

' respectively, andincluding elongated engageable portions positioned ina plane spaced from but substantially parallel to the plane of movementof said blade and disposed at different angles, respectively, withrespect to the direction of movement of said blade means with saidrotatable insulator, whereby said horns remain in engagement during saidlongitudinal movement, and engage or disengage only during said pivotalmovement of said blade means.

3. In a circuit interrupter, contacts at least one of which is movableinto and out of intimate engagement with the other substantiallyrectilinearly, and being substantially laterally movable from a remoteposition to a position in proximity thereto, arcing horns mounted onsaid contacts, respectively, and including elongated engageable portionsin a plane spaced from but substantially parallel to the plane ofmovement of said movable contact, and disposed at different angle withrespect to said lateral direction of movement of said movable contact,whereby said arcing horns remain in engagement during said rectilinearmovement, and are engaged or disengaged during said lateral movement.

4. Circuit interrupting means including a contact movable into and outof engagement with rality of raised substantially parallel linecontacting portions extending substantially in the direction of saidrectilinear movement for engagement with said movable contact.

5. Circuit interrupting means including a contact movable into and outof engagement with a cooperating contact, stop means adjacent saidcooperating contact, rotatable supporting and actuating means for saidmovable contact, said movable contact being eccentrically movablymounted on said supporting means for movement therewith into and out ofengagement with said stop means and for limited relative movementthereto substantially rectilinearly into and out of engagement with saidcooperating contact, and one of said contacts including a, plurality ofspaced substantially parallel line contacting por-v tions extending inthe direction of said rectilinear movement for engagement with at leastone side of the other of said contacts.

6. In a disconnecting switch, a switch blade, rotatable supporting andactuating means for said blade comprising spaced supporting plates forpivotally mounting said blade therebetween, a side plate connecting saidspaced plates for maintaining them in spaced relation, and said sideplate having an elogated slot therethrough for receiving an intermediateportion of said blade to permit pivotal movement thereof limited to theextent of said slot.

7. In a disconnecting switch, a switch blade, rotatable supporting andactuating means for said blade comprising spaced supporting plates forpivotally mounting said blade therebetween, a side plate connecting saidspaced plates for maintaining them in spaced relation, said side sideplate having an elongated slot therethrough for receiving anintermediate portion of said blade to permit pivotal movement thereoflimited to the extent of said slot, and the space between said spacedplates being otherwise open so that one end of a terminal member mayalso extend into the space between said plates so as to be pivotallymounted therebetween.

8. In a disconnecting switch, a switch blade, rotatable supporting andactuating means for said blade comprising spaced supporting plates forpivotally mounting said blade therebetween, a side plate connecting saidspaced plates for maintaining them in spaced relation, said side platehaving an elongated slot therethrough for receiving an intermediateportion of said blade to permit pivotal movement thereof limited to meextent of said slot, the space between said spaced plates beingotherwise open so that one 1 end of a terminal member may also extendinto the space between said plates so as to be pivotally mountedtherebetween on an axis coinciding with the axis of rotation of saidsupporting and actuating means, and the pivot axis of said blade beingoffset from the pivot axis of said terminal member and supporting andactuating means.

9. In a circuit interrupter, contacts at least one of which is movableinto and out of intimate engagement with the other, arcing horns mountedon said contacts, respectively, and including elongated engageableportions in a plane spaced from but substantially parallel to the planeof movement of said movable contact, and disposed at different angleswith respect to the direction of movement of said movable contact,whereby said arcing horns are engaged or disengaged only when saidcontacts are disengaged.

10. In a circuit interrupter, rotatable insulating means, h'ollowmounting means on said rotatable insulating means, a 'slot through onewall of said mounting means, a generally T- shaped blade memberincluding a blade portion smaller than said slot and extendingtherethrough and a cross head portion in said mounting means, and oneend of said cross head portion pivotally mounted in said mounting meanson an axis eccentric relative to the axis of said insulating means.

11. In a circuit interrupter, rotatable insulating means, hollowmounting means on said rotatable insulating means, a slot through onewall of said mounting means, a generally T- shaped blade memberincluding a blade portion smaller than said slot and extendingtherethrough and a cross head portion of greater extent than said slotand located in said mounting means, and said cross head portionpivotally mounted in said mounting means on an axis eccentric relativeto the axis of said insulating means.

12. In a circuit interrupter, rotatable insulating means, hollowmounting means on said rotatable insulating means, a slot through onewall of said mounting means, a generally T- shaped blade memberincluding a blade portion smaller than said slot and extendingtherethrough and a cross head portion in said mounting means, and oneend of said cross head portion pivotally mounted in said mounting meansbeyond one end of said slot on an axis eccentric relative to the axis ofsaid insulating means, whereby the other end of said cross head portionis adapted to engage said mounting means adjacent the other end of saidslot for limiting relative movement of said blade member in onedirection.

13. In a disconnecting switch, a switch blade rotatable supporting andactuating means for said blade comprising spaced supporting plates forpivotally mounting said blade therebetween, a side plate connecting saidspaced plates for maintaining them in spaced relation, said side platehaving an elongated slot therethrough for receiving an intermediateportion of said blade to permit pivotal movement thereof limited to theextent of said slot, and the space between said spaced plates being openat least at the side opposite said side plate so that one end of aterminal member may extend into the space between said plates at saidopposite side thereof, and means pivotally mounting said one end of saidterminal member between said plates.

14. In a disconnecting switch, a rotatable insulating support, a switchblade and a terminal member pivotally mounted on said support ondifierent pivot axes for movement relative thereto and each other, asingle flexible shunt means electrically connecting said blade andterminal member and spanning said pivots, and means limiting relativepivotal movement of said blade and support.

HERBERT L. RAWLINS. CARL A. RINGBLOOM.

